Switch module and inverter

Abstract

An electric apparatus includes: a first stacked body in which a first semiconductor chip having a first switch is stacked on a first mounting portion; a second stacked body in which a second semiconductor chip having a second switch is stacked on a second mounting portion; a temperature sensor provided in the first stacked body to detect a temperature of the first switch; and a current sensor provided in the second stacked body to detect a current flowing through the second switch. The second stacked body has a heat dissipation property higher than that of the first stacked body.

What is claimed is: 
     
         1 . A switch module comprising:
 a first stacked body in which a first semiconductor chip having a first switch is stacked on a first mounting portion;   a second stacked body in which a second semiconductor chip having a second switch is stacked on a second mounting portion, an on-resistance of the second switch being lower than an on-resistance of the first switch;   a current sensor provided in the second stacked body to detect a current flowing through the second switch;   a signal terminal connected to the first switch and the second switch; and   a coating resin that coats the first stacked body, the second stacked body, and the signal terminal, to expose a portion of the signal terminal, wherein the signal terminal includes a current sensor terminal to which the current sensor is connected, and includes no terminal to detect a current flowing through the first switch.   
     
     
         2 . The switch module according to  claim 1 , wherein a heat dissipation of the second stacked body is higher than a heat dissipation of the first stacked body. 
     
     
         3 . A switch module comprising:
 a first stacked body in which a first semiconductor chip having a first switch is stacked on a first mounting portion;   a second stacked body in which a second semiconductor chip having a second switch is stacked on a second mounting portion, an on-resistance of the second switch being lower than an on-resistance of the first switch;   a temperature sensor provided in the first stacked body to detect a temperature of the first switch;   a current sensor provided in the second stacked body to detect a current flowing through the second switch;   a signal terminal connected to the first switch and the second switch; and   a coating resin that coats the first stacked body, the second stacked body, and the signal terminal, to expose a portion of the signal terminal, wherein the signal terminal includes   a terminal to which the temperature sensor is connected, and   a current sensor terminal to which the current sensor is connected, and   the signal terminal includes no terminal to detect a temperature of the second switch and no terminal to detect a current flowing through the first switch.   
     
     
         4 . The switch module according to  claim 1 , wherein the first switch and the second switch are connected in parallel. 
     
     
         5 . The switch module according to  claim 1 , wherein
 a material of the first mounting portion is the same as a material of the second mounting portion, and   a volume of the first mounting portion is smaller than a volume of the second mounting portion.   
     
     
         6 . The switch module according to  claim 5 , wherein
 each of the first mounting portion and the second mounting portion has an exposed surface exposed from the coating resin, a first direction being defined along the exposed surface, a second direction being defined along the exposed surface and orthogonal to the first direction,   the first stacked body and the second stacked body are arranged in the first direction, an overlapping region is defined in which a projection region of the first mounting portion projected in the second direction overlaps with a projection region of the second mounting portion projected in the first direction, and   a part of the signal terminal is located in the overlapping region.   
     
     
         7 . The switch module according to  claim 6 , wherein the signal terminal includes a common terminal electrically connected to each of the first switch and the second switch. 
     
     
         8 . The switch module according to  claim 1 , wherein
 at least a part of the second mounting portion includes a different material different from a material of the first mounting portion, and   a thermal conductivity of the second mounting portion is higher than a thermal conductivity of the first mounting portion.   
     
     
         9 . The switch module according to  claim 1 , further comprising:
 a first joining member provided between the first semiconductor chip and the first mounting portion to join the first semiconductor chip and the first mounting portion; and   a second joining member provided between the second semiconductor chip and the second mounting portion to join the second semiconductor chip and the second mounting portion, wherein   at least a part of the second joining member includes a different material having a thermal conductivity higher than that of the first joining member.   
     
     
         10 . The switch module according to  claim 1 , wherein an area of the first mounting portion is different from an area of the second mounting portion. 
     
     
         11 . The switch module according to  claim 1 , wherein
 the signal terminal includes a gate terminal as a common terminal,   the gate terminal is connected to a gate electrode of the first switch, and   the gate terminal is connected to a gate electrode of the second switch.   
     
     
         12 . The switch module according to  claim 1 , wherein the first switch and the second switch are configured to be simultaneously energized. 
     
     
         13 . An inverter comprising:
 a high-side switch module and a low-side switch module connected in series between a first power supply bus bar and a second power supply bus bar,   the high-side switch module includes a first switch module, a third switch module, and a fifth switch module,   the low-side switch modules include a second switch module, a fourth switch module, and a sixth switch module,   the first switch module and the second switch module are connected to a U-phase bus bar,   the third switch module and the fourth switch module are connected to a V-phase bus bar,   the fifth switch module and the sixth switch module are connected to a W-phase bus bar, and   each of the first switch module, the second switch module, the third switch module, the fourth switch module, the fifth switch module, and the sixth switch module is the switch module according to  claim 1 .